Means for burning lime



l J. T. MABEE 5 6,318

r11 3, 1924 2 Sheets-Sheet 1 i W I May 25 1926. 1,586,318

J. T. MABEE MEANS FOR BURNING LIME File pril 5. 1924 2 Sheds-Sheet 2 Patented May 25, 1926.

UNITED STATES PATENT OFFICE.

JOHN '1. MABEE, OF CHICAGO, ILLINOIS, ASSIGNOR TO RAYMOND BROS. ENGINEERING 00., OF CHICAGO, ILLINOIS, A CORPORATION 01' ILLINOIS- MEANB I03 BURNING LIME.

Application med April 3, 1924. Serial No. 703,843.

M invention relates to means for burning ime, and it has for its principal object the provision of a new and im roved form and arrangement of parts, by w ich a standard upri ht, stationary lime kiln can be fired b t e use of pulverized fuel. In firing a iln of this type by the use of pulverized fuel, it is necessary that the organization and arran ement be such that there shall be very litt e, if an slag carried into the kiln proper, and it as been the particular object of my invention to provide such an arrangement of parts. B my improved construction, by which I ave succeeded in reventing the entrance of slag into the ki a proper, I have prevented the discoloration of the lime which would be efl'ected by the sla if permitted to mix with the rock 1n the ki 11.

Another important feature of my invention pertains to the maintenance of the draft through the kiln. In a construction of this sort, in which the draft must be maintained directly through the body of the mass of materials formin the contents of the structure, which in this case is in the form of broken lime rock, it is essential that the interstices between the pieces of rock shall not be filled either by the com lete crumbling of the pieces, or in any ot er manner as by the entrance of some foreign material. When a standard upright kiln 1s filled .for starting its 0 eration, it requires the maintenance of a tire for a period of from three or four days up to eight or ten days, or even lon er, before the contents of the kiln is broug t to the condition justifying the first draw of lime. During this preliminary firing for brin ing the kiln into production, it is particu arl difficult to maintain the draft through t e kiln, and it has been one of the special objects of my invention to rovide a construction by the use of vwhu i this preliminary firin can be successfuliy effected by the use 0 pulverized fuel.

It is another object of my invention to improve devices of this t pe in sundry details, hereinafter pointe out. The referred means by which I have accomplis ed my objects are illustrated in the drawings and are hereinafter specifically described. That which I believe to be new and desire to cover by Letters Patent is set forth in the claims.

In the drawings,

Fig. 1 is a front view of my improved kiln, partly broken away.

Fig. 2 is a horizontal sectional view through the kiln, being taken substantially at line 2-2 of Fig. 1. g

Fig. 3 is a vertical section taken at line 33 of Fig. 2; and

Fig. 4 is a vertical section taken at line 44 of Fig. 2.

Referring to the several figures of the drawings, in which comes ondmg parts are indicated by the same re erence characters, indicates a kiln, the body of which is in the form of a verticallydisposed shell, the bottom portion of which is oval, as is clearl shown in Fig. 2. The kiln comprises a com ustion chamber 11, at each side of the body of the kiln, at its lower portion, such combustion chambers being preferably built with and incorporated as art of the kiln proper. As is clearly indicated in Fig. 3, each of the combustion chambers is referably provided with a lining of firerick as is usual in such constructions. In the construction shown, the wall of the kiln is thickened and extended laterally at each side of each of the combustion chambers for providing a foundation 12 for the kiln. As will be readily understood, the body of the kiln ordinarily extends upwardly a distance of from to feet, being provided with means at the upper end for feeding the lime rock to the body of the kiln. Inasmuch as this feeding means forms no part of the present invention, it is not believed to be necessary to show it herein. At the bottom,

the body of the kiln opens into a hop er 13,

of an suitable type, as is shown in ig. 4, for rawing the completed product from the kiln, the hopper being below the level of the combustion chambers.

As is best shown in Fig. 4, each of the combustion chambers is rovided with means for feeding pulverized uel thereto through the medium of a stream of air or other gas from any suitable source, such means comprising a nozzle 14 extending through a sleeve 15 opening downwardl into the combustion chamber. As is rea ily understood in the operation of devices of this type, the

stream of gas and fuel entering through the nozzle 14 causes, by induction, the entrance of auxiliary air through the sleeve 15 about the nozzle. A lighting port 16 is provided through the wall of the combustion chamber a short distance below the nozzle 14, as is best shown in Fig. 4.

In my improved construction, communication is afforded between the combustion chambers 11 and the bod of the kiln by means of eyes 17, four 0 such eyes being rovided between each combustion chamber and the body of the kiln. In the construction shown, these eyes are arranged in pairs, one pair being above the other pair, one eye of each pair being located directly above the corresponding eye of the other pair. It is not believed that this particular arrange ment of the eyes is essential, but I do believe that it is im ortant that the eyes be arranged at different evels, at least one eye being arranged above the level of one or more of the other eyes.

In the front face of each of the combustion chambers, there is arran ed a punch hole 18, the level of the punch Iiole 18 being between that of theupper eye 17 and that of the lower eye 17. B this arrangement, access is had to both 0 the eyes from the same punch hole 18. In the construction shown, I have also provided a number of air openings 19 for the admission of auxiliary air for insuring the complete combustion of the pulverized fuel. At the bottom of each combustion chamber, I have provided an ash door 20, which is to be utilized for cleaning out the combustion charnbers. The lighting port; 16, the punch hole 18, and the ash door 20 are preferably provided with closing means of any suitable type, as illustrated, while the air openings 19 are ordinarily closed b the insertion of a brick when it is desire to limit the admission of auxiliary air.

Additional punch holes have been provided in the wall of the bod of the kiln between the combustion cham ers 11. One of these punch holes is located above the level of the combustion chambers, as is shown in Fig. 4, being indicated by the numeral 21. The other punch hole is located at substantially the same level as that of the 7 lower eyes 17, such lower punch hole being indicated b the numeral 22. These holes are prefera 1 provided with closing means of any suita le type, as illustrated in the drawings. As will be readily understood, access is had to the upper eyes 17 through the punch holes 21, while access is had to the lower eyes 17 through the punch holes 22.

For assisting in keeping down the temperature within the combustion chambers, as hereinafter described, I have provided a pipe 23 extending into the combustion chamber and connected with any suitable source of water or steam, being provided with a plurality of openings 24 in its upper face for spraying such water or steam upwardly into the flame within the combustion chamber.

In operation, the kiln is filled from the top with lime stone, 'in the usual manner; pulverized fuel is fed through the nozzles 14 from a suitable source, and the streams of fuel are ignited by the use of the ports 16. The fire then is maintained in the combustion chambers, the kiln itself acting as the flue, the hot gases passing upwardly through the mass of materials in the kiln. At intervals, as may be necessary, the eyes are cleared of any material which may have gathered there in such a Way as to prevent passage of the hot ases into the body of the klln. This punc ing out is preferably effected by the use of a bar through the opening 18. At the end of from three to five days, or more, according to weather conditions and other circumstances, the conditions will be found to be correct for a draw of four or five tons of lime through the ho per 13, the kiln, of course, being refilled rom the top to replace th material withdrawn.

I have found in practice in the use of my improved structure and operation, that after the kiln is brought into production, it is unnecessary to punch out the eyes 17 other than at the times of the successlve draws of lime at intervals of three and one-half to six hours. This is very different from the necessity in connection with a. hand fired kiln, provided with the old form ofeyes where it has been necessary ordinarily to punch out the eyes at intervals of an hour to insure the desired freedom of passage of the flame through the eyes and the production of the desired draft through the combustion chambers.

It sometimes happens that when the line is withdrawn at the bottom of the kiln, there is a tendency for the material to stick along the walls at a higher point. In view of this, I have provided the punch holes 21 for providin access to the interior of the kiln for ena ling a worker to loosen the material by the use of a bar. These punch holes 21 can also be used for access to the inner ends of the e cs 17.

In my im rove construction, the combustion cham rs 11 are proportioned so as to insure the production of a large volume of mellow heat therein rather than a small volume of intense heat. This is of very considerable importance from the standpoint of maintenance of the lining of the kiln and of the combustion chambers, but it is of even greater importance with respect to the formation of liquid slag. I have found in practice that by the use of a comparatively much larger combustion chamber than those formerly used, I am enabled with the use ofpulverized fuel to maintain the desired lar e volume of mellow heat for effective operation of the kiln without the formation of liquid slag. I have found that by the use'of pulverized fuel for firing a kiln provided with my improved construction, I am enabled to produce from 20 to 30 or 40% more lime than could be done in the same kiln by hand firing before my improvements were installed. I have found that through the medium of the large volume of mellow heat produced by the use of my improved construction, the slag is not liquefied and it is a comparatively easy matter to keep the eyes 17 cleared. Moreover, there is no difficulty under such circumstances about maintaining the desired draft, since the slag is not carried into the body of the kiln, but is deposited at the bottom of "the combustion chamber in the form of small particles of ash or in the form of an easily broken honeycomb or sponge. This feature is of utmost importance in the operation of the kiln.

For the purpose of assisting in keeping down the temperature within the combustion chamber for freezing the slag particles and for maintaining the desired large volume of mellow heat, water or steam is preferably sprayed from the pipe 23.

So far as I am aware, I am the first in the art to provide anarrangement of parts by the use of which a stationary kiln of the upright standard type shown can be fired successfully with pulverized fuel so as to maintain continuously the required freedom of draft through the material in the kiln and so as to prevent the discoloration of the lime by slag passing into the body of the kiln. Inasmuch as these features are essential to a really successful operation of a kiln by the use of puverized fuel, which I have accomplished by my improved construction comprising my novel arrangements of the eyes 17, and comprising the provision of a combustion chamber so proportioned and arranged as to insure the production of a large volume of mellow heat so as to prevent the formation of liquid slag, I desire to claim broadly the constructions by which these results have been attamed, and my claims are to be construed accordingly.

By the use of my improved construction, by which the use of pulverized fuel is made successful, the health and comfort conditions of the workmen are wonderfully improved. In the use of the standard kiln of this type by hand firing, the smoke at the top of the kiln, where the men work feeding in the stone and preparing for the feeding, is very often so dense that it is difficult or impossible to see the men from the ground or feet away. In the use of my improved construction with pulverized fuel, the hot gases emerging from the top of the kiln carry practically no ash or other foreign substance.

While I prefer to employ substantially the form of construction illustrated in the drawings, it will be understood that I do not desire to limit myself to the details of construction except so far as they are specifically claimed, inasmuch as it is evident that changes may well be made in the construction without departing from the spirit of my invention.

I claim:

1. The process of burning lime by the use of pulverized fuel, which comprises placing lime stone in a stationary kiln, burning the fuel in a comparatively large separate combustion chamber so as to produce a large volume of mellow heat in the combustion chamber, and conducting the heated gases into the kiln and through the interstices between the broken limestone fragments held therein.

2. The process of burning lime by the use of pulverized fuel, which comprises plac ing the lime stone in a stationary kiln, burning the fuel in a comparatively large separate combustion chamber so as to produce a large volume of mellow heat in the combustion chamber, introducing steam into the lower part of the combustion chamber for assisting in preventing the formation of liquid slag, and conducting the heated gases into the kiln and through the interstices between the broken limestone fragments held therein.

3. The rocess of burning lime by the use of pulverized fuel, which comprises placing the lime stone in a stationary kiln, burning the fuel in a comparatively large separate combustion chamber so as to produce a large volume of mellow heat in the combustion chamber, spraying steam against the flame at the-lower part of the'combustion chamber for assisting in preventing the formation of li uid slag, and conducting the heated gases into the kiln and through the interstices between the broken limestone fragments held therein.

1 4. A kiln for burning limestone comprising a vertically elongated chamber for holding the limestone and adapted to serve as a flue for products of combustion and slag collecting, a large combustion chamber at one side of the kiln chamber and in open communication therewith through a comparatively small opening, and means for feeding pulverized solid fuel into the combustion chamber at a position remote from the opening whereby substantially complete combustion of the pulverized fuel will take place in the combustion chamber with deposition of slag, and the heated gases will be drawn out through the opening and between the limestone fragments by the flue action of the kiln chamber.

5. A kiln for burning limestone. comprising a vertically elongated chamber for holding the limestone and adapted to serve as a flue for products of combustion, a large combustion and slag collecting chamber at one side of the kiln chamber and in open communication therewith through a plurality of comparatively small openings, and means for feeding pulverized solid fuel into the combustion chamber at a position remote from the openings whereby substantially complete combustion of the pulverized t'ue] will take place in the combustion chamber, and the heated gases will be drawn out through the openings and between the limestone fragments by the flue action of the kiln chamber.

6. A kiln for burning limestone comprising a vertically elongated chamber for bolding the limestone and adapted to serve as a flue for products of combustion, a large combustion and slag collecting chamber at one side of the kiln chamber and in open communication therewith through a plurality of comparatively small openings, means -for feeding pulverized solid fuel downwardly into the combustion chamber at the top and at a place remote from the said openings where y substantially complete combustion of the pulverized fuel will take place in the combustion chamber, and the heated gases will be drawn out through the openings and between the limestone fragments by the flue action of the kiln chamber, and means for spraying steam into the lower portion of the combustion chamber.

JOHN T. MABEE.

drawn out through the opening and between the limestone fragments by the flue action of the kiln chamber.

5. A kiln for burning limestone comprising a vertically elongated chamber for holding the limestone and adapted to serve as a flue for products of combustion, a large combustion and slag collecting chamber at one side of the kiln chamber and in open communication therewith through a plurality of con'iparatively small openings, and means for feeding pulverized solid fuel into the combustion chamber at a position remote from the openings whereby substantially complete combustion of the pulverized 'fuel will take place in the combustion chamber, and the heated gases will be drawn out through the openings and between the limestone fragments by the flue action of the kiln chamber.

6. A kiln for burning limestone compriscombustion chamber, and the heated gases will be drawn out through the openings and between the limestone fragments by the flue action of the kiln chamber, and means for spraying steam into the lower portion of the combustion chamber.

JOHN T. MABEE.

Gertificate of Correction.

It is hereby certified that in Letters Patent No. 1,586,318,

fgranted May 25, 1926,

u on the application of John T. Mabee. of Chicago, Illinois. or an improvement in l ueans for Burning Lime, errors appear in the printed specification requiring correction as follows: Page 2. line 109, for the word line read lime: page 3, lines 120 and 121, claim 4, strike out the words and slag collecting and insert the same to follow after the word combustion line 121, same claim; and that the said Letters Patent should be read With these corrections therein that the same may conform to the record of the case in the Patent ()ifice.

Signed and sealed this 22d day of June, A. D. 1926.

'M: J. MOORE, Acting Commissioner of Patents.

Certificate of Correction.

It is hereby certified that, in Letters Patent No. 1.586318, ranted May '25, 1926, u fin the application of John T. Mabee. of Chicago, Illinois, or an improvement in cans for Burning Lime, CIIOIS appear in the printed specification requiring correction as follows: Page 2, line 109, for the word line read lime: page 3, lines 120 and 121, claim 4, strike out the words and slag collecting and insert the same to follow after the word combustion line 121, same claim; and that the said Letters Patent should be read with these wrrecfiions therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 22d day of June, A. D. 1926.

[smrh] M. J. MOORE,

Acting Commissioner of Patents. 

